Is this correct and if so, is it seen as impolite? I'm looking for a friendly way of saying "as you want" in conversation when speaking to someone and they've suggested several ways of doing something where I really don't mind which option we take.
Yes, "wie du magst" or "wie du möchtest" or "ich richte mich da gerne nach dir" are good ways of saying it.
You could make sure to also state that you don't mind because that's not implied. ("Mir ist es egal", "Mir ist beides recht", "ich finde beides gut", "Ich finde alle Vorschläge gut")
Uttering "Von mir aus." would be a reaction to a single suggestion, and would mean "I'm not really happy with it, but I'm ok to concede." However, "Von mir aus können wir das gern machen." is perfectly polite.
How all of this is perceived always also depends on context, like in any language. You can probably also give nonverbal clues about how you mean it.
"Wie Du magst" even though translating as "How(ever) you like (it)" has a risk of being understood as "suit yourself" or even "Whatever" and those are not very friendly terms. Since you're apparently already Dooching, "Wie Du möchtest" ("As you (would) want") takes the edge off. Not so when Seeching. "Wie Sie möchten" gets stepped up to "Wie Sie wünschen" which translates as "As you wish" which means the same, but with less risk to be misinterpreted, due to its more respectful and humble attitude. All these can be said by themselves.